Abstract: A highly efficient electromagnetic actuator which can reduce leakage of the magnetic flux is provided. The electromagnetic actuator comprises a first coil 31, a movable body 2 adapted to move on the central axis of the first coil 31, a first stator 11 covering the top face, bottom face and outer peripheral face of the first coil 31, and a permanent magnet 15 adapted to firmly latch the movable body 2 at one end point of its movable range. A second stator 12 adapted to control the magnetic flux generated from the permanent magnet 15 is provided in succession with the first stator 11. By providing the second stator 12, when releasing the movable body 2 from its firmly latched state, the permanent magnet 15 is not inversely excited or demagnetized.

Abstract: A highly efficient electromagnetic actuator which can reduce leakage of the magnetic flux is provided. The electromagnetic actuator comprises a first coil 31, a movable body 2 adapted to move on the central axis of the first coil 31, a first stator 11 covering the top face, bottom face and outer peripheral face of the first coil 31, and a permanent magnet 15 adapted to firmly latch the movable body 2 at one end point of its movable range. A second stator 12 adapted to control the magnetic flux generated from the permanent magnet 15 is provided in succession with the first stator 11. By providing the second stator 12, when releasing the movable body 2 from its firmly latched state, the permanent magnet 15 is not inversely excited or demagnetized.

Abstract: A needle 2 includes a plunger member 21 and a collar member 22, and is provided to be reciprocable from a latch position to a latch release position inside a stator 1. A first magnet coil 31 has sufficient electromagnetic power to put in a latch state the needle 2 which is in a latch release state on energization. A permanent magnet 4 has sufficient absorption power for absorbing a collar member 22 of the needle 2 put in the latch state by the electromagnetic power of the first magnet coil 31 and maintaining the latch state even when the first magnet coil 31 is in a non-energized state. A second magnet coil 32 can diminish magnetic fluxes of the permanent magnet 4 and change the needle 2 from the latch state to the latch release state on energization. Thus, energy efficiency is improved by varying how to energize the magnet coils according to the state of a load side.

Abstract: In a closing magnetic circuit, when a movable contact is in contact with a fixed contact and a switching device is closed, N and S poles of a permanent magnet attract the fixed member in a direction in which the movable contact is pressed against the fixed contact. In an opening magnetic circuit, when the movable contact is separated from the fixed contact and the switching device is open, one of the N and S poles of the permanent magnet attracts the fixed member in a direction in which the movable contact is separated from the fixed contact. An operating electromagnet winding increases and decreases the magnetism in the closing magnetic circuit and opening magnetic circuit. With this configuration, it is possible to realize an operating apparatus for a switching device using a simple mechanism and assure a stable operation by producing a great contact load.

Abstract: {W—CuxSb-balance Cu} alloy is employed for contacts. As the anti-arcing constituent in the alloy W or WMo in a content of 65 to 85%, of grain diameter 0.4 to 9 &mgr;m is employed. As auxiliary constituent, CuxSb is employed, the content of the CuxSb being 0.09 to 1.4 weight %, the x being x=1.9 to 5.5, the grain diameter being 0.02 to 20 &mgr;m, and the mean distance between grains being 0.2 to 300 &mgr;m. As conductive constituent, Cu or CuSb solid solution is employed, the Sb content present in solid solution form in the CuSb solid solution being less than 0.5%. As a result, not only is dispersion of CuxSb, which is evaporated on subjection to arcing, reduced, but also generation of severe cracks, which have an adverse effect in terms of occurrence of restriking. Arcing at the contacts surfaces is prevented, suppressing dispersion and exfoliation of W grains.

Abstract: The contact material of the present invention comprises: an anti-arcing constituent consisting of at least one TiC, V and VC of which the content is 30˜70 volume % and whose mean particle (grain) size is 0.1˜9 &mgr;m; C whose content is 0.005˜0.5 weight % with respect to the anti-arcing constituent, whose diameter is 0.01˜5 &mgr;m when its shape is calculated as spherical, and which is in non-solid solution condition or condition in which it does not form a chemical compound; and a conductive constituent consisting of Cu and constituting the balance.

Abstract: A vacuum valve which has a contact material having a constituent of high electrical conductivity such as Cu and an anti-arcing constituent including Cr in which particles whose particle size is in the range 0.1.about.150 .mu.m represent at least 90 volume %, and a ratio defined by the formula (.alpha..sub.900 -.alpha..sub.50).times.100/(.alpha..sub.900) for this contact material has a value of 8-12% and is the coefficient of thermal expansion of the contact material .alpha..sub.50 is the coefficient of thermal expansion of the contact material at 50.degree. C. The formation of channels generated at the interfaces of the Cr particles and the Cu matrix after undergoing the brazing step is suppressed, enabling the static withstand-voltage, contact resistance, and the breaking performance characteristics of the vacuum valve to be stabilized.

Abstract: An electrode arrangement of a vacuum circuit breaker for making and breaking electrical connection. The electrode arrangement has: a pair of contact members which are adopted for making contact to and release from each other by relatively moving to and from each other along a predetermined direction; a pair of electrically conductive bars being connected to the above pair of contact members, respectively, for providing electric conduction to the contact members; and a magnetizing device with a magnetic body for generating magnetic field parallel to the predetermined direction between the contact members. The magnetic body is composed of an iron alloy comprising 0.02 to 1.5% by weight of carbon and iron. The iron alloy may further contain at least one of manganese and silicon.

Abstract: A method of manufacturing a semiconductor device comprising a ceramics cylinder, a metal seal member closing an open end of the cylinder, a semiconductor element located within the cylinder and having electrodes, and leads or electrodes connected to the electrodes of the semiconductor element and extending from the cylinder. The method comprises the steps of coating powder of active metal consisting of Ti and/or Zr on the end face of the ceramics cylinder without heating the ceramics cylinder, in an amount of 0.1 mg/cm.sup.2 to 10 mg/cm.sup.2, mounting a layer of brazing filler metal on the end face of the ceramics cylinder, which have been coated with the powder of the active metal, placing the metal seal member on the layer of brazing filler metal, and heating the ceramics cylinder, the metal seal member, and the layer of brazing filler metal, thereby melting the layer of brazing filler metal and, thus, brazing the metal seal member to the open end of the ceramics cylinder.

Abstract: A method of manufacturing an air-tight ceramic container is disclosed. This method includes the steps of coating an active metal consisting of Ti and/or Zr on an opening end face of a ceramic tubular member in an amount of 0.1 to 10 mg/cm.sup.2, thereby forming an active metal layer, placing a brazing filler metal on the active metal layer, placing a metal cover member for shielding an opening portion of the ceramic tubular member so that a peripheral portion end face of the metal cover member is in contact with the brazing filler metal, and melting the brazing filler metal by heating, thereby brazing the metal cover member to the opening end face of the ceramic tubular member.

Abstract: A vacuum switch having two main electrodes encased in a vacuum vessel to be operable in opening and closing the main electrodes, is provided with a contact piece made of a copper-chromium alloy secured or formed on at least one of the main electrodes. The operational property of the main electrodes is substantially improved by flowing and interrupting an electric current of a predetermined current density for a number of times through the two main electrodes for improving surface condition of the contact piece by forming a recrystallized layer over the outer surface of the contact piece.